The present invention is directed to a method and apparatus for removing welded outer lead bonds of TAB tape leads, and more particularly to the removal of defective electronic components having a plurality of outer lead bonds of TAB tape which are bonded to an electrical contact of a support, and still more particularly, is directed to a method for removing gold to gold TAB outer lead weld bonds.
When an electronic component fails it often becomes economically necessary to remove the failed device rather than replace the entire substrate. In the case where the electronic component has electrical leads which are solder bonded, this can be easily done by remelting the soldered connections and removing the defective components such as disclosed in U.S. Pat. No. 4,934,582. However, with certain hard welded electrical contact bonds, particularly such as gold to gold thermocompression and thermosonic bonds, such bonds have generally been considered irreparable because of the inability to remelt these bonds without damaging the underlying support. However, many users of TAB technology utilize gold plated tape and gold plated substrate pads because of military specifications and the desired high reliability. One repair method is suggested in U.S. Pat. No. 4,991,286 which removes the failed component by cutting off the leads and leaving the remnants of the old outer lead bonds in place. However, this method has not been widely accepted because of the required expensive tooling, reduced reliability, and/or more required substrate area.
The present method and apparatus removes the old outer lead bond remnants or stubs, leaving a bondable surface and unencumbered pad for subsequent TAB integrated circuit bonding in a process substantially identical to the original assembly process using the same tooling, equipment and procedure.